Association of Bovine Respiratory Disease during the Pre-Weaning Period with Blood Cell Counts and Circulating Concentration of Metabolites, Minerals, and Acute Phase Proteins in Dairy Calves Transported to a Calf Raising Facility

Simple Summary Dairy calves are often subjected to transportation at a young age and this may increase their risk of bovine respiratory disease (BRD). Many previous investigations evaluated the association of BRD with blood cells and with the concentration of metabolites, minerals, and proteins associated with an inflammatory response. However, these factors can also be altered by transportation stress, and information regarding how these variables are associated with BRD in calves that undergo transportation stress in early life is limited. This study aimed to evaluate the association of BRD with several variables related to biomarkers of metabolism and inflammation in dairy calves transported to a calf raising facility within the first few days of life. Blood was collected at 7, 17, 34, and 56 days of age, and several variables were associated with BRD. For instance, calves diagnosed with BRD within their first 30 days had elevated haptoglobin, a biomarker of inflammation, at 7 days of age, but at 56 days of age, the concentration of this biomarker was reduced in comparison to healthy calves. Our findings demonstrate how these variables are associated with BRD after calves undergo long distance transportation.Abstract Our objective was to investigate the association of bovine respiratory disease (BRD) occurring within the first 56 days of life with blood cell counts and the circulating concentration of metabolites, minerals, and acute phase proteins throughout the pre-weaning period in dairy calves transported to a heifer raising facility within their first week of life. Data from 305 calves transported from dairies in Minnesota to a calf raising facility in New Mexico within their first four days of life were used in this retrospective cohort study. Blood samples were collected at 7, 17, 34, and 56 days of life for the analysis of blood cell counts, biochemistry, and the concentration of acute phase proteins. Blood urea nitrogen, albumin, GLDH, CK, P, Na, K, Cl, Zn, Hp, SAA, and monocyte counts were associated with BRD status throughout or at least at one of the time points evaluated in this study. In conclusion, several hematological variables were associated with BRD status in dairy calves that underwent transportation stress in early life.